Due to the complex nature of  Aprils Command of the Month, the Professional AutoCAD Users Group will only be discussing the AutoCAD side of ASE.  Most Windows databases run in the same fashion and most are compatible with AutoCAD's ASE.  It is strongly suggested that you review and understand all of the information given in the AutoCAD help areas regarding this topic.  Also keep in mind that some databases will connect to AutoCAD easier than others using the provided SQL  (Structured Query Language) and ODBC (Open Database Connection) drivers.  In any case you should do the research before you start this venture, it will save you time and money.

Database links are connections that can be established between AutoCAD drawing objects and an external database record.  The link allows you to open database rerecord by using the ASELINKS command or by using the Links option of the External Database portion of the Tools pull down and selecting an object.  Once you have selected a linked object in AutoCAD you can edit the database record.  A (DA) Displayable Attribute is an unnamed block object that lets you present database information in a drawing.  When you add a Displayable Attribute to a drawing it will be automatically linked to the record from which you created it.

Connecting to a database

Before you can create link to an external database you must first set the database connection.  Select the Administrator option from the External Database portion of the Tools pull down.  We are going to select DB3 for our database object environment.  To do this, highlight the DB3 object and click on the Connect button.  When you do this youre Connect to Environment dialogue box will appear.  Here you need to enter your name and password and click OK.   Notice on your connection column that "No" changed to "Yes", the available column changed to "Yes" and the registered column remains at "No".  That is because we have yet to load an environment, catalogue or schema (schematic).  Now that you have established a database environment, select the Catalog radio button followed by the Schema, then the Table radio buttons.  This must be done in this order.  Database connections follow a ridged hierarchy, starting with the Catalog and ending with the Table is a must.   After selecting the Table radio button, select the Employee table and click on the Link Path Names Button. Notice the three headings in the Key Selection Window showing the column Schema of the database table.  In order to register a column to the link path, select the desired column(s) and click the On button. Notice the New field in the Link Path is now enabled.   Select the shown columns and enter the word Employee in the New field in the Link Path and click on the New button.  It is a good idea to name the link path the same name as the selected column for easy reference however it is not necessary.  Repeat the same steps creating a link path for the Computer column selecting all of the columns.  Once you have completed adding link paths, the Administrator dialogue box will appear now showing the Link Path names in the Set By list and the Registered column is showing "Yes".

Linking

With the established linked paths you can now link AutoCAD objects to your database records.  Select Rows from the External Database portion of the Tools pull down and select the Employee link from the Link Path Pull down and click the Open Cursor button.  You will now see the first record in the Employee table.  Here is where you will either locate and establish a link to a database record or edit a record.  By clicking on the Next button you can scroll though the columns.  When you locate the record you are looking for click on the link button.  You can have as many links to a single object as you need.  After selecting the Link button the dialogue box will turn into a cursor for selection of an object.

Displayable Attributes (DA)

If  you need to display the information from a database record in an AutoCAD drawing.  It can be done using the same method as setting up a link with one exception.  Instead of selecting the Make Link button you will select the Make DA button.  This will invoke the Make Display Attributes dialogue box.  Here you select the Table Columns and the Text Formatting  that you will place in your AutoCAD drawing.  Click OK and place the information in your drawing.   Good Luck.